1、BRITISH STANDARD AEROSPACE SERIES BS ISO 14950:2004 Space systems Unmanned spacecraft operability ICS 49.140 BS ISO 14950:2004 This British Standard was published under the authority of the Standards Policy and Strategy Committee on 2 April 2004 BSI 2 April 2004 ISBN 0 580 43607 1 National foreword
2、This British Standard reproduces verbatim ISO 14950:2004 and implements it as the UK national standard. The UK participation in its preparation was entrusted to Technical Committee ACE/68, Space systems and operations, which has the responsibility to: A list of organizations represented on this comm
3、ittee can be obtained on request to its secretary. Cross-references The British Standards which implement international publications referred to in this document may be found in the BSI Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Search” faci
4、lity of the BSI Electronic Catalogue or of British Standards Online. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Compliance with a British Standard does not of itself confer immunity from legal obligation
5、s. aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. Summary of pag
6、es This document comprises a front cover, an inside front cover, the ISO title page, pages ii to vi, pages 1 to 24, an inside back cover and a back cover. The BSI copyright notice displayed in this document indicates when the document was last issued. Amendments issued since publication Amd. No. Dat
7、e Comments Reference number ISO 14950:2004(E)INTERNATIONAL STANDARD ISO 14950 First edition 2004-02-15 Space systems Unmanned spacecraft operability Systmes spatiaux Oprabilit des satellites non habits BSISO14950:2004IS:05941 O4002(E) DPlcsid Fremia ihTs PDF file mya ctnoian emdebt dedyfepcaes. In c
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12、1121-HC 02 av leT. 4 + 10 947 22 1 11 xaF0 947 22 14 + 9 74 E-mial coirypthgis.o gro We bwww.is.o groii ISO 4002 Allr ithgsr esedevrBSISO14950:2004IS:05941 O4002(E) I SO 4002 All irthgs ersedevr iiiContents Page Foreword iv 0 Introduction v 0.1 Spacecraft operation v 0.2 Spacecraft operability. v 0.
13、3 Conventions . vi 0.4 Guidelines for applicability . vi 1 Scope 1 2 Normative references . 1 3 Terms and definitions. 1 4 Abbreviated terms. 6 5 Autonomy levels . 7 6 General requirements. 8 6.1 Observability . 8 6.2 Commandability 8 6.3 Compatibility . 8 6.4 Security 8 6.5 Safety 8 6.6 Flexibility
14、 9 6.7 Efficiency . 9 6.8 Testability 9 6.9 Applicability matrix. 10 7 Detailed requirements 10 7.1 Spacecraft observability requirements. 10 7.2 Spacecraft commandability requirements . 12 7.3 Memory management . 14 7.4 On-board processing functions 15 7.5 Equipment/subsystem-specific requirements
15、. 19 Annex A (informative) Mission constants 23 BSISO14950:2004IS:05941 O4002(E) iv I SO 4002 All irthgs ersedevrForeword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards
16、 is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take p
17、art in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to
18、 prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility t
19、hat some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 14950 was prepared by Technical Committee ISO/TC 20, Aircraft and space vehicles, Subcommittee SC 14, Space systems and operations. BSIS
20、O14950:2004IS:05941 O4002(E) I SO 4002 All irthgs ersedevr v0 Introduction 0.1 Spacecraft operation The operation of a spacecraft is an activity performed from a mission control centre in order to: a) ensure availability of mission and science products/services or data; b) carry out routine housekee
21、ping operations; c) recover from on-board contingencies; d) manage on-board resources in order to maximize the provision of products/services and the mission lifetime. 0.2 Spacecraft operability The operability is a feature of the spacecraft itself that enables a specified ground segment comprising
22、hardware, software, personnel, and procedures, to operate the space segment during the complete mission lifetime of the spacecraft, by using a minimum of resources, while maximizing the quality, quantity, and availability (or timeliness of delivery) of mission products, without compromising spacecra
23、ft safety. The key factors that determine the operability of a spacecraft are: a) the ability to control the spacecraft in any nominal or non-nominal scenario in order to maintain the mission availability; b) the capability to manage on-board resources and to maximize the mission lifetime; c) the ex
24、tent to which its operations are routine and non-hazardous, thus minimizing ground segment resources for all operations including fault avoidance and correction; d) the flexibility of the design for spacecraft reconfiguration, including software, in orbit; e) the reliability of operations and robust
25、ness against human error; f) the simplicity of the space and ground segment required to fulfil the mission requirements and respect the mission constraints; g) the autonomous capability of the space systems; h) the complexity and interdependence of the flight system. Spacecraft operability can be qu
26、antified by the following measures: the capability to detect abnormal trends or status and the speed of reconfiguration back to an operational mission to minimize duration of outage; the number of staff required to operate the spacecraft during the operational phase and to maintain the ground segmen
27、t; the qualification level of staff required to perform operations; the quantity and complexity of mission-specific knowledge required to perform operations. Spacecraft operability is an input to total life cycle cost. Increased operability will, in general, decrease operations and maintenance costs
28、 but increase development costs. Thus, specific operability goals should be determined by careful balancing of costs, risks, and schedules for both procurement and operations/maintenance. The key objectives of this International Standard are: BSISO14950:2004IS:05941 O4002(E) vi I SO 4002 All irthgs
29、ersedevr to ensure that a spacecraft operates in a safe and cost-effective manner and may be operated with an optimized workload; to facilitate and/or enhance the tasks of preparation for, execution and evaluation of, spacecraft check-out and mission operations activities; to facilitate the tasks of
30、 spacecraft prime contractors when preparing a proposal in answer to an international request for proposal (RFP). This International Standard is written in such a way that technological advances will not invalidate the International Standard. Thus, this International Standard is not project or machi
31、ne specific. The operation of the space segment to meet mission-specific requirements is outside the scope of this International Standard. 0.3 Conventions Requirements are identified by an acronym, which indicates the nature/grouping of the requirement, followed by a serial number, and appear in bol
32、d type (e.g. OBSERV-0010). The serial number comprises four digits starting at 0010 and is incremented by 10 to facilitate configuration control for later versions of the document. Where a major requirement is broken down into subsidiary requirements, the serial number is extended to reflect this st
33、ructure (e.g. TEST-1010.1 would represent the first sub-requirement of requirement 1 relating to testability). General operability requirements are numbered in the range 0010 to 0999, while detailed operability requirements are numbered in the range 1010 to 1999. Some of the detailed operability req
34、uirements in Clause 6 are only relevant for a given level of on-board autonomy. In such cases, the corresponding autonomy level (as defined in Clause 4), is indicated as a super- script following the requirement ID. For example, FAULT-1100 C3 . Some requirements introduce quantities for which values
35、 cannot be defined across the board but will need to be defined on a mission-by-mission basis (e.g. time intervals, response times, etc.). These are termed mission constants and are identified within this International Standard in “” (for example, ) and, where appropriate, typical values may be indi
36、cated. These mission constants are also summarised, for information only, in Annex A. 0.4 Guidelines for applicability This International Standard specifies a set of general operability requirements and a set of detailed operability requirements. Many of the detailed operability requirements apply t
37、o specific on-board functions. The general operability requirements are intended to be applicable to spacecraft missions of all classes (i.e. science, telecommunications, meteorology, Earth observation, geostationary, low-Earth orbiting and interplanetary). The steps for designing a new mission are
38、normally: a) the mission constraints are identified (e. g. design constraints, cost constraints); b) the mission operations concept is developed, including the level of on-board autonomy for routine and contingency operations; c) the spacecraft is designed, based on a) and b) above. The applicabilit
39、y of the detailed requirements in this International Standard should be determined during step a). As indicated above, some of the detailed requirements are only applicable to a given level of autonomy. During step c), the mission operations concept and the applicability of the detailed requirements
40、 may be iterated. BSISO14950:2004INTENRATIONAL TSANDADR IS:05941 O4002(E)I SO 4002 All irthgs ersedevr 1Space systems Unmanned spacecraft operability 1 Scope This International Standard defines the essential properties pertaining to the operation of unmanned spacecraft and defines requirements and g
41、uidelines for spacecraft on-board functions in order to enable a specified ground segment to operate the spacecraft in any nominal or predefined contingency situation. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated referenc
42、es, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 14620-1:2002, Space systems Safety requirements System safety 3 Terms and definitions For the purposes of this document, the following terms and definitio
43、ns apply. 3.1 General terms 3.1.1 commandability ability of the ground to safely control and configure all the equipment and software on-board the spacecraft as required for the execution of the nominal mission, for failure identification and recovery, for performance assessment and for system maint
44、enance subsequent to performance change and system degradation 3.1.2 compatibility extent to which the design of the space segment conforms with the existing ground segment infrastructure (if any) and with existing operational practices 3.1.3 efficiency optimum distribution of tasks between the grou
45、nd and space segments taking into account cost, complexity, technology and reliability 3.1.4 flexibility capacity to configure and make optimum use of existing on-board functions, space-Earth communications links, any redundancy built into the design in order to meet reliability targets, as well as
46、the capacity to optimize mission products according to the mission events BSISO14950:20041IS:05941 O4002(E) 2 I SO 4002 All irthgs ersedevr3.1.5 observability ability to acquire operationally significant information for physical and logical parameters on-board the spacecraft NOTE 1 This information
47、is delivered to the ground through the telemetry channel and/or made available to on-board processors. NOTE 2 The definition of observable parameters is a key requirement for operating spacecraft, monitoring the behaviour of all on-board systems, performing diagnosis of anomalies, and collecting suf
48、ficient information for feedback into ground-based models. 3.1.6 operation spacecraft activity performed from a mission control centre NOTE See the Introduction, 0.1, for further details defining spacecraft operation. 3.1.7 operability spacecraft feature of the spacecraft itself that enables a speci
49、fied ground segment to operate the space segment during the complete mission lifetime of the spacecraft NOTE See the Introduction, 0.2, for further details defining spacecraft operability. 3.1.8 safety extent of on-board protection against failure and the provision of fail-safe modes of operation 3.1.9 security extent of on-board protection against unauthorized access to on-board telecommand functions, jamming of the telecommand channel,
